Blending of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) with poly(ethyleneimine) as an active layer in depletion-mode organic thin film transistors

The conjugated polymer poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT-PSS) is usually applied in fabricating electrodes of devices. In this work, the applications to organic a thin film transistor with the introduction of poly(ethyleneimine) (PEI) into the PEDOT-PSS are investigated. The conductivity of PEDOT-PSS can be reduced by incorporating PEI into PEDOT-PSS, which can be applied as an active layer instead of electrodes for devices application. Based on the PEDOT-PSS blended with PEI, the fabricated devices posses a depletion-mode transistor behavior with the on/off ratio of about 103 is used. Meanwhile, the role of PEI in PEDOT-PSS to modulate the channel conductivity is discussed.